A physical uplink control channel (PUCCH) format 2 may convey two to four channel state information (CSI) bits to the eNB. In carrier aggregation, a CSI configuration of each serving cell may be independently configured by radio resource control (RRC) layers to have a particular periodicity, starting offset, PUCCH mode, etc. However, the transmission of CSI using PUCCH format 2 is done in primary cell only. When more than one CSI reporting for multiple serving cells collide with each other in the same subframe, only CSI for one serving cell may be transmitted and the others dropped. Further, when any CSI transmission using PUCCH format 2 and hybrid automatic repeat request-acknowledgement (HARQ-ACK) transmission using PUCCH format 2 in carrier aggregation collide in the same subframe, HARQ-ACK using PUCCH format 3 is transmitted and all CSIs are dropped. Frequent dropping of CSIs may decrease operational efficiencies of a network.